Your SAN score hovers between 100 and 0. Being exposed to traumatic experiences and supernatural weird shit can bring it down. Watch out! If it goes low enough, you'll have a lot of difficulty getting through the day.
The typical SAN score is somewhere between 75 and 95. People who put special effort into ignoring unpleasant facts, or who don’t really try to build a world model so much as memorize “what the right thing to do” is in a wide variety of situations, or who have a high level of epistemic learned helplessness may have SAN scores in the high 90s. People who are both curious enough to be weird and privileged enough to have a safety net, like tenured professors or eccentric billionaires, may be high-functioning despite SAN between 50 and 80, but this is difficult for most people.
SAN is a presence, not the absence of something. Low SAN can mark someone off, while high SAN is unremarkable, so it seems like the absence of something called “insanity.” Nope! SAN is a specific set of beliefs and instincts that are built up with great effort and maintained with what is considerable inconvenience, because having them is so useful. (Having low SAN doesn’t automatically result in something that shows up in the DSM, except in the sense that literally everything corresponds to something in the DSM, but the DSM is part of a universal cultural project of trying to keep people at high SAN and policing those who do not.)
The specific beliefs that are part of high SAN vary from culture to culture, but in general they include things like:
- the world makes sense
- everything will work out in the end
- bad people will be punished and the good will be rewarded
- but if good people suffer there’s an unknown good reason for it
- I am one of the good people
- causality flows from past to future
- the adults know what they’re doing
- I can trust my senses most of the time
- my emotions are mostly appropriate responses to my situation
- people have meaningful subjective experiences and laundry machines don’t
and so on. Continuing with the relationship between SAN and our society’s concept of a mental disorder, if you believe in the rituals of mental health enough to go through them as an enthusiastic-ish participant, you probably already have a decent SAN and the rituals will work for placebonic reasons. (The rituals may also work for reasons adverted on the tin, like changing your brain chemistry or exposing you to evidence that high-SAN beliefs are true.)
SAN is reduced by exposure to evidence that its percepts are false. SAN loss is thus an expression of rationality, not irrationality. If you meet an honest-to-goodness ghost that is evidence, among other things, that
- you can’t trust your senses
- science doesn’t work
- elite common sense is wrong
- etc
At low SAN, you can’t rule out many possibilities, and you especially can’t rule out many bad possibilities. This is mostly bad. If your SAN is really high you may come off as shallow, naive, and robotic, and maybe you’d benefit from an Ayahuasca trip, but if you’re a paranormal investigator in a modern horror setting or whatever, you want all the SAN you can hold onto.
SAN loss should largely be a choice, albeit often the best of several bad choices. Exposure to horrid mysteries should largely grant the option to simply suppress the information, forgoing the option to acknowledge or reason from or use it in any way. This healthy suppression is what most people do most of the time (the average person IS exposed to all sorts of stuff that would drive them mad reasonably often, if they thought obsessively about it, which they quite reasonably don’t.) But if you’re a humble flapper investigating Yog-Sothoth or whatever, maybe you need to acknowledge some of that. Pick your demons wisely.